Genomes and Genes

Species

magnetoencephalography

Summary

Summary: The measurement of magnetic fields over the head generated by electric currents in the brain. As in any electrical conductor, electric fields in the brain are accompanied by orthogonal magnetic fields. The measurement of these fields provides information about the localization of brain activity which is complementary to that provided by electroencephalography. Magnetoencephalography may be used alone or together with electroencephalography, for measurement of spontaneous or evoked activity, and for research or clinical purposes.

..This is problematic for the computation of event-related desynchronization (ERD) on MEG data, since ERD relies on a correspondence between the signal maximum and the location of the neuronal generator...

..This means that we formulate a null hypothesis (identical probability distribution in the different experimental conditions) and show that the nonparametric test controls the false alarm rate under this null hypothesis...

Interactions between functionally specialized brain regions are crucial for normal brain function. Magnetoencephalography (MEG) and electroencephalography (EEG) are techniques suited to capture these interactions, because they provide ..

Suresh D MuthukumaraswamyCardiff University Brain Research Imaging Centre, School of Psychology and CUBRIC and Schools of Chemistry and Biosciences, Cardiff University, Cardiff, United KingdomProc Natl Acad Sci U S A 106:8356-61. 2009

..functional MRI (fMRI) of the blood oxygen level-dependent (BOLD) response and electroencephalography or magnetoencephalography (MEG) recordings of neural oscillations being 2 of the most popular approaches...

..In this paper we describe a means to characterize resting state brain networks independently using magnetoencephalography (MEG), a neuroimaging modality that bypasses the hemodynamic response and measures the magnetic fields ..

The equation for the magnetic lead field for a given magnetoencephalography (MEG) channel is well known for arbitrary frequencies omega but is not directly applicable to MEG in the quasi-static approximation...

Limitations of traditional magnetoencephalography (MEG) exclude some important patient groups from MEG examinations, such as epilepsy patients with a vagus nerve stimulator, patients with magnetic particles on the head or having magnetic ..

..Tinnitus as a phantom phenomenon is related to hyperactivity and reorganization of the auditory cortex. Magnetoencephalography studies demonstrate a correlation between gamma band activity in the contralateral auditory cortex and the ..

..The aim of the present work is to evaluate the value of preoperative magnetoencephalography (MEG) imaging of functional connectivity to predict the results of intraoperative electrical stimulation (..

EEG and MEG (magnetoencephalography) are widely used to study functional connectivity between different brain regions. We address the question whether such connectivity patterns display an optimal organization for information processing...

..Competing large-scale neuronal theories of language are discussed in light of the data summarized. Neurobiological perspectives on the problem of serial order of words in syntactic strings are considered in closing...

Measuring functional connectivity using MEG: methodology and comparison with fcMRI

..we show that the phase pattern of theta band (4-8 Hz) responses recorded from human auditory cortex with magnetoencephalography (MEG) reliably tracks and discriminates spoken sentences and that this discrimination ability is ..

..We argue that these data are best explained within the framework of predictive coding in which sensory activity is compared with top-down predictions and only unexplained activity propagated through the cortical hierarchy...

..Perspectives for future research will be discussed in relationship to methodological issues, the utility of neural oscillations as a biomarker, and the neurodevelopmental hypothesis of schizophrenia...

..we administered benzodiazepines to healthy adults and monitored cortical oscillatory activity by means of magnetoencephalography. Benzodiazepine increased the power and decreased the frequency of beta oscillations over rolandic areas...

..We also applied the proposed beamformer to two sets of auditory-evoked MEG data, and the results clearly demonstrated the method's capability of reconstructing spatio-temporal activities of neural sources...

Neuromagnetic indicators of tinnitus and tinnitus masking in patients with and without hearing loss

..The cortical topography and frequencies involved in the alpha and beta networks suggest that these networks may be involved in attentional and executive, particularly motor planning, processes, respectively...

Magnetoencephalography: From SQUIDs to neuroscience. Neuroimage 20th anniversary special edition

b>Magnetoencephalography (MEG), with its direct view to the cortex through the magnetically transparent skull, has developed from its conception in physics laboratories to a powerful tool of basic and clinical neuroscience...

..Delineating the SV precisely is a challenge during the presurgical evaluation of patients with epilepsy. Magnetoencephalography (MEG) recordings enable determination of the brain sources of epileptic spikes using source localization ..

..state of the sensory system adjusted to up- or downregulate processing according to anticipation? We used magnetoencephalography to investigate whether prestimulus alpha band activity (8-14 Hz) reflects allocation of attentional ..

Use of magnetoencephalography (MEG) to study functional brain networks in neurodegenerative disorders

..Based on the rationale that damaged brain tissue is disconnected from the physiological interactions among healthy areas, this study aimed to map the functionality of brain areas according to their connectivity with other areas...

Nathan CashdollarUniversity College London Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, United KingdomProc Natl Acad Sci U S A 106:20493-8. 2009

..Using magnetoencephalography in healthy adults and patients with bilateral hippocampal sclerosis, we distinguish this hippocampus-..

Detection and localization of hippocampal activity using beamformers with MEG: a detailed investigation using simulations and empirical data

..Furthermore, the results suggest that ongoing oscillations in sensory cortices may optimize the processing of sensory stimuli with the same mechanism as noise sources in intrinsic stochastic resonance...

..90%, respectively, in one session and vice versa for the other one, and we traced brain responses using magnetoencephalography. Results show that activation in the middle occipital gyrus (MOG) was significantly enhanced for the ..

..Here we investigated the test-retest reliability of graph metrics of functional networks derived from magnetoencephalography (MEG) data recorded in two sessions from 16 healthy volunteers who were studied at rest and during ..

Performance of an MEG adaptive-beamformer technique in the presence of correlated neural activities: effects on signal intensity and time-course estimates

The spatial resolution achievable using magnetoencephalography (MEG) beamformer techniques is inhomogeneous across the brain and is related directly to the amplitude of the underlying electrical sources [Barnes and Hillebrand, Hum Brain ..

Neural dynamics for facial threat processing as revealed by gamma band synchronization using MEG

..The results localize human visual gamma-band activity in frequency, time and space and the described methods allow its further investigation with great sensitivity...

Statistical control of artifacts in dense array EEG/MEG studies

M JunghoferDepartment of Psychology, University of Konstanz, GermanyPsychophysiology 37:523-32. 2000

With the advent of dense sensor arrays (64-256 channels) in electroencephalography and magnetoencephalography studies, the probability increases that some recording channels are contaminated by artifact...

Robust Bayesian estimation of the location, orientation, and time course of multiple correlated neural sources using MEG

David P WipfDepartment of Radiology and Biomedical Imaging, University of California San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USANeuroimage 49:641-55. 2010

..Empirical results on both simulated and real data sets verify the efficacy of this approach...

..Our findings demonstrate that physiologically meaningful information can be extracted from heavily contaminated MEG signals and pave the way for further analysis of combined MEG-LFP recordings in DBS patients...

..on somatic awareness and its relationship to mind-body interactions in three specific areas: a) the use of magnetoencephalography to document alterations in somatic awareness in mind-body interactions, b) combined use of both "dry" and "..

..imaging approach, capitalizing on the complementary strengths of psychophysical paradigms, fMRI and magnetoencephalography, to achieve the following specific aims: In Aim 1 we will test all relevant aspects of the relationship ..

..EEG) and to a lesser degree on combined near-infrared spectroscopy (NIRS) and EEG or magnetoencephalography (MEG). There are however some fundamental limitations to existing multimodal neuroimaging approaches...

..Unfortunately, this FR from the mesial temporal lobe does not appear to be detectable over the scalp with magnetoencephalography (MEG) or electroencephalography (EEG) according to the intracranial data of Gotman and his coworkers from ..

..3) Unilateral STN DBS in PD alters activity in the ipsilateral premotor cortex. Magnetoencephalography (MEG) will measure the kinetics and localization of cortical magnetic fields evoked by high and low ..

..by applicant): At University of Arkansas for Medical Sciences we have installed the world's first magnetoencephalography (MEG) system specifically designed and modified for fetal and newborn assessment...

..by applicant): The overarching goal of this proposal is to use evidence-based methodology to evaluate Magnetoencephalography (MEG) as a clinical tool for evaluation and planning of surgical treatment for patients with epilepsy...

..Magnetic fields of this order are greater than endogenous neuronal fields detected in tech- nologies like magnetoencephalography, and have been shown previously to be measurable by MRI in some contexts...

..parent questionnaires and objective behavioral, audiological, and functional brain imaging tests [magnetoencephalography and electroencephalography] will be used to explore the impact of APT on auditory processing and autistic ..

..of electrophysiological biomarkers of impaired receptive language functioning in autistic children using magnetoencephalography. This proposal seeks to translate these clinical findings of impaired auditory-evoked potentials (AEP) to ..

..To meet this goal, we have implemented an innovative approach that that uses magnetoencephalography (MEG) neuroimaging methods and neurobehavioral methods to identify the neural processes that serve motor ..

..study, using novel tasks developed for this K08 project, functional measures (electroencephalography and magnetoencephalography) of auditory activity throughout the brain will be obtained with 50 controls and 50 patients...

Neurofeedback by means of non-invasive surface Electroencephalography (EEC) or Magnetoencephalography (MEG) of the human brain provides an important mechanism for control of brain- computer-interfaces (BCI) or potential treatment for ..

..To test this hypothesis, high temporal resolution methods of electro- and magnetoencephalography (EEC and MEG) will be integrated with the high spatial resolution method of functional magnetic resonance ..

..In study 2, brain activity will be recorded during learning with fMRI and during remembering with magnetoencephalography (MEG), a technique ideally suited to determining precisely when brain activity is occurring...

..of event-related functional magnetic resonance imaging (fMRI) with the high temporal resolution of magnetoencephalography (MEG) and electroencephalography (EEG) to identify the regions involved and the timing of their ..

..This Phase I research will evaluate the feasibility of developing a new non-invasive magnetoencephalography (MEG) sensor, called a babySQUID, capable of measuring spontaneous and evoked electrical activity of the ..

..capitalizing on the complementary strengths of psychophysical paradigms, functional and diffusion MRI, and magnetoencephalography to achieve the following specifiC aims: 1) To study the nature of the prefrontal cortex representations ..

..In this application, we propose experiments that combine a relatively rare neuroimaging technique (Magnetoencephalography (MEG)) with a well-characterized sample in order to accelerate our knowledge of the pathophysiology of AD...